Abstract: Bacteria use the cell wall to control the organization of many sub-cellular components in space and time. The cell wall functions as the 'cytoskeleton'in bacteria and protects cells from mechanical stress. The enormous osmotic pressure across the cell wall (>1 atm) requires that cell growth be tightly regulated, as small defects in the cell wall are catastrophic. A molecular understanding of the assembly, properties, and mechanisms for localizing essential proteins to the cell wall will provide fundamental insight into the inner working of this essential structure. The identification of proteins that are localized to the cell wall and regulate and remodel it will open the door to a new chapter in antibiotic development by rebooting an interest in this cellular material as a drug target. My laboratory will use a multidisciplinary approach to study the bacterial cell wall by drawing on our experience in chemical biology, biochemistry, biophysics, and materials science and engineering. Our focus centers upon two aims: 1. We will develop a high-throughput, materials science-based technique for measuring the mechanical properties of bacterial cell walls. Using this capability we will analyze the entire genome-wide collection of Escherichia coli single gene mutants to identify proteins that modulate its physical properties. 2. We will develop a suite of materials science-based approaches for controlling cell wall curvature in bacteria and will study how the shape of the cell wall regulates the formation of lipid microdomains, which in turn participates in the intracellular localization of cytoplasmic proteins. We will develop small molecules that target the proteins identified in these aims and will use them to study the function of these molecules in vivo using a chemical biological approach. The results of these studies will shed new light on essential processes in bacterial cells and will uncover mechanisms for regulating bacterial physiology. These mechanisms and molecules will stimulate the development of potent classes of antibiotics that have applications in preventing and treating human infections. Public Health Relevance: This research will identify new proteins and mechanisms that regulate the structure and organization of the bacterial cell wall. The results will lead to the development of new classes of antibiotics against pathogenic bacteria.